TECHNICAL FIELD
[0001] The present disclosure relates generally to optical devices and fabrication methods
and, more specifically, to a white light-emitting diode ("LED") package for virtual
reality liquid crystal display.
BACKGROUND
[0002] Display technologies have been widely used in a large variety of applications in
daily life, such as smartphones, tablets, laptops, monitors, TVs, projectors, vehicles,
virtual reality ("VR") devices, augmented reality ("AR") devices, mixed reality ("MR")
devices, etc. Non-emissive displays, such as liquid crystal displays ("LCDs"), liquid-crystal-on-silicon
("LCoS") displays, or digital light processing ("DLP") displays, may require a backlight
unit to illuminate a display panel. Self-emissive displays may display images through
emitting lights with different intensities and colors from light-emitting elements.
A self-emissive display may also function as a locally dimmable backlight unit for
a non-emissive display panel. A compact display engine with dynamic zonal brightness
control with improved display performance and power budget is highly desirable, which
can be incorporated into a variety of devices, and is suitable for portable devices
including hand-held, wrist-worn, or head-mounted devices, etc.
SUMMARY OF THE DISCLOSURE
[0003] Consistent with an aspect of the present disclosure, a light-emitting diode ("LED")
package is provided. The LED package includes a first LED disposed with the space
defined by the package housing, and configured to emit a first light having a blue
wavelength range. The blue wavelength range has a peak wavelength ranging from about
440 nm to about 480 nm. The LED package further includes a second LED disposed within
the space, and configured to emit a second light having a red wavelength range. The
red wavelength range has a peak wavelength ranging from about 610 nm to about 680
nm. The LED package further includes a phosphor filler filling the space and configured
to absorb a portion of the first light to emit a third light having a green wavelength
range. The green wavelength range has a peak wavelength ranging from about 510 nm
to about 570 nm.
[0004] In accordance with an aspect of the present disclosure, there is provided a light-emitting
diode ("LED") package, comprising: a package housing defining a space; a first LED
disposed with the space defined by the package housing, and configured to emit a first
light having a blue wavelength range, wherein the blue wavelength range has a peak
wavelength ranging from about 440 nm to about 480 nm; a second LED disposed within
the space defined by the package housing, and configured to emit a second light having
a red wavelength range, wherein the red wavelength range has a peak wavelength ranging
from about 610 nm to about 680 nm; an a phosphor filler filling the space and configured
to absorb a portion of the first light to emit a third light having a green wavelength
range, wherein the green wavelength range has a peak wavelength ranging from about
510 nm to about 570 nm.
[0005] In some embodiments, the first LED and the second LED are configured to be individually
or independently drivable by individual driving circuits.
[0006] In some embodiments, the LED package further comprises a controller configured to
individually control driving currents provided by the driving circuits to the first
LED and the second LED to adjust a color of an output light of the LED package.
[0007] In some embodiments, a concentration of the phosphor filler is adjustable to adjust
a color of an output light of the LED package.
[0008] In some embodiments, the LED package further comprises a third LED disposed inside
the package housing, and configured to emit the first light having the blue wavelength
range, wherein the blue wavelength range has the peak wavelength ranging from about
440 nm to about 480 nm.
[0009] In some embodiments, the first LED and the third LED are connected in series, and
are configured to be drivable by a same driving circuit.
[0010] In some embodiments, the driving currents provided to the first LED and the second
LED are the same, or are different.
[0011] In some embodiments, the second LED is disposed between the first LED and the third
LED.
[0012] In some embodiments, the first LED and the third LED are disposed side by side along
a first row, the second LED is disposed along a second row, and the second row is
parallel with the first row or the same as the first row.
[0013] In some embodiments, the first LED, the second LED, and the third LED are disposed
side by side along a same row.
[0014] In some embodiments, the second LED has a size that is greater than the first LED.
[0015] In some embodiments, the LED package, further comprises a fourth LED disposed inside
the package housing, and configured to emit the second light having the red wavelength
range with the peak wavelength ranging from about 610 nm to about 680 nm.
[0016] In some embodiments, the first LED and the third LED are connected in series and
are configured to be drivable by a first driving circuit, and the second LED and the
fourth LED are connected in series and are configured to be drivable by a second,
different driving circuit, and wherein the LED package further includes a controller
configured to individually control driving currents provided by the first and second
driving circuits to adjust a color of an output light of the LED package.
[0017] In some embodiments, the first LED and the third LED are blue LEDs, and the second
LED and the fourth LED are red LEDs, and the blue LEDs and the red LEDs are arranged
in an alternating pattern.
[0018] In some embodiments, the first LED and the third LED are arranged side by side along
a first row, and the second LED and the fourth LED are arranged side by side along
a second row, the second row is parallel with the first row.
[0019] In some embodiments, the first LED, the second LED, the third LED, and the fourth
LED are arranged side by side along a same row.
[0020] In some embodiments, the LED package, further comprises a third LED disposed inside
the package housing, and configured to emit the second light having the red wavelength
range with the peak wavelength ranging from about 610 nm to about 680 nm.
[0021] It will be appreciated that any features described herein as being suitable for incorporation
into one or more aspects or embodiments of the present disclosure are intended to
be generalizable across any and all aspects and embodiments of the present disclosure.
Other aspects of the present disclosure can be understood by those skilled in the
art in beam of the description, the claims, and the drawings of the present disclosure.
The foregoing general description and the following detailed description are exemplary
and explanatory only and are not restrictive of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The following drawings are provided for illustrative purposes according to various
disclosed embodiments and are not intended to limit the scope of the present disclosure.
In the drawings:
FIGs. 1A and 1B illustrate schematic diagrams of a conventional white LED package;
FIGs. 2A and 2B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 2C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 2A and 2B, according to an embodiment of the present disclosure;
FIGs. 3A and 3B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 3C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 3A and 3B, according to an embodiment of the present disclosure;
FIGs. 4A and 4B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 4C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 4A and 4B, according to an embodiment of the present disclosure;
FIGs. 5A and 5B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 5C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 5A and 5B, according to an embodiment of the present disclosure;
FIGs. 6A and 6B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 6C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 6A and 6B, according to an embodiment of the present disclosure;
FIGs. 7A-7C illustrate schematic diagrams of a white LED package, according to an
embodiment of the present disclosure;
FIGs. 8A and 8B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 8C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 8A and 8B, according to an embodiment of the present disclosure;
FIGs. 9A and 9B illustrate schematic diagrams of a white LED package, according to
an embodiment of the present disclosure;
FIG. 9C illustrates a schematic diagram of driving circuits of the white LED package
shown in FIGs. 9A and 9B, according to an embodiment of the present disclosure;
FIGs. 10A-10C illustrate schematic diagrams of a white LED package, according to an
embodiment of the present disclosure;
FIG. 11A illustrates a schematic diagram of a display system, according to an embodiment
of the present disclosure;
FIG. 11B illustrates a schematic diagram of an illuminator that may be included in
the display system shown in FIG. 11A, according to an embodiment of the present disclosure;
FIG. 11C illustrates a schematic diagram of a display system, according to an embodiment
of the present disclosure;
FIG. 12A illustrates a schematic diagram of an artificial reality device, according
to an embodiment of the present disclosure;
FIG. 12B schematically illustrates a cross-sectional view of half of the artificial
reality device shown in FIG. 12A, according to an embodiment of the present disclosure;
and
FIG. 12C schematically illustrates a cross-sectional view of the artificial reality
device shown in FIG. 12A, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0023] Embodiments consistent with the present disclosure will be described with reference
to the accompanying drawings, which are merely examples for illustrative purposes
and are not intended to limit the scope of the present disclosure. Wherever possible,
the same reference numbers are used throughout the drawings to refer to the same or
similar parts, and a detailed description thereof may be omitted.
[0024] Further, in the present disclosure, the disclosed embodiments and the features of
the disclosed embodiments may be combined. The described embodiments are some but
not all of the embodiments of the present disclosure. Based on the disclosed embodiments,
persons of ordinary skill in the art may derive other embodiments consistent with
the present disclosure. For example, modifications, adaptations, substitutions, additions,
or other variations may be made based on the disclosed embodiments. Such variations
of the disclosed embodiments are still within the scope of the present disclosure.
Accordingly, the present disclosure is not limited to the disclosed embodiments. Instead,
the scope of the present disclosure is defined by the appended claims.
[0025] As used herein, the terms "couple," "coupled," "coupling," or the like may encompass
an optical coupling, a mechanical coupling, an electrical coupling, an electromagnetic
coupling, or any combination thereof. An "optical coupling" between two optical elements
refers to a configuration in which the two optical elements are arranged in an optical
series, and a light output from one optical element may be directly or indirectly
received by the other optical element. An optical series refers to optical positioning
of a plurality of optical elements in a light path, such that a light output from
one optical element may be transmitted, reflected, diffracted, converted, modified,
or otherwise processed or manipulated by one or more of other optical elements. In
some embodiments, the sequence in which the plurality of optical elements are arranged
may or may not affect an overall output of the plurality of optical elements. A coupling
may be a direct coupling or an indirect coupling (e.g., coupling through an intermediate
element).
[0026] The phrase "at least one of A or B" may encompass all combinations of A and B, such
as A only, B only, or A and B. Likewise, the phrase "at least one of A, B, or C" may
encompass all combinations of A, B, and C, such as A only, B only, C only, A and B,
A and C, B and C, or A and B and C. The phrase "A and/or B" may be interpreted in
a manner similar to that of the phrase "at least one of A or B." For example, the
phrase "A and/or B" may encompass all combinations of A and B, such as A only, B only,
or A and B. Likewise, the phrase "A, B, and/or C" has a meaning similar to that of
the phrase "at least one of A, B, or C." For example, the phrase "A, B, and/or C"
may encompass all combinations of A, B, and C, such as A only, B only, C only, A and
B, A and C, B and C, or A and B and C.
[0027] When a first element is described as "attached," "provided," "formed," "affixed,"
"mounted," "secured," "connected," "bonded," "recorded," or "disposed," to, on, at,
or at least partially in a second element, the first element may be "attached," "provided,"
"formed," "affixed," "mounted," "secured," "connected," "bonded," "recorded," or "disposed,"
to, on, at, or at least partially in the second element using any suitable mechanical
or non-mechanical manner, such as depositing, coating, etching, bonding, gluing, screwing,
press-fitting, snap-fitting, clamping, etc. In addition, the first element may be
in direct contact with the second element, or there may be an intermediate element
between the first element and the second element. The first element may be disposed
at any suitable side of the second element, such as left, right, front, back, top,
or bottom.
[0028] When the first element is shown or described as being disposed or arranged "on" the
second element, term "on" is merely used to indicate an example relative orientation
between the first element and the second element. The description may be based on
a reference coordinate system shown in a figure, or may be based on a current view
or example configuration shown in a figure. For example, when a view shown in a figure
is described, the first element may be described as being disposed "on" the second
element. It is understood that the term "on" may not necessarily imply that the first
element is over the second element in the vertical, gravitational direction. For example,
when the assembly of the first element and the second element is turned 180 degrees,
the first element may be "under" the second element (or the second element may be
"on" the first element). Thus, it is understood that when a figure shows that the
first element is "on" the second element, the configuration is merely an illustrative
example. The first element may be disposed or arranged at any suitable orientation
relative to the second element (e.g., over or above the second element, below or under
the second element, left to the second element, right to the second element, behind
the second element, in front of the second element, etc.).
[0029] When the first element is described as being disposed "on" the second element, the
first element may be directly or indirectly disposed on the second element. The first
element being directly disposed on the second element indicates that no additional
element is disposed between the first element and the second element. The first element
being indirectly disposed on the second element indicates that one or more additional
elements are disposed between the first element and the second element.
[0030] The term "processor" used herein may encompass any suitable processor, such as a
central processing unit ("CPU"), a graphics processing unit ("GPU"), an application-specific
integrated circuit ("ASIC"), a programmable logic device ("PLD"), or any combination
thereof Other processors not listed above may also be used. A processor may be implemented
as software, hardware, firmware, or any combination thereof.
[0031] The term "controller" may encompass any suitable electrical circuit, software, or
processor configured to generate a control signal for controlling a device, a circuit,
an optical element, etc. A "controller" may be implemented as software, hardware,
firmware, or any combination thereof. For example, a controller may include a processor,
or may be included as a part of a processor.
[0032] A liquid crystal display ("LCD") used in a virtual reality device (or virtual reality-liquid
crystal display ("VR-LCD")) often incorporates white light-emitting diode ("LED")
packages within its backlight unit ("BLU") to produce a white light to illuminate
an LCD panel. Conventional white LED packages in the BLU may rely on Yttrium Aluminum
Garnet ("YAG") LEDs or Nitride LEDs, which can only achieve a standard red, green,
blue ("sRGB") color gamut (that covers about 72% of the National Television System
Committee ("NTSC") gamut). To achieve a DCI-P3 color gamut (that covers 26% more color
space than sRGB color gamut), blue LEDs and quantum dot color conversion sheets may
be needed in the BLU.
[0033] FIGs. 1A and 1B illustrate schematic diagrams of a conventional white LED package
100. FIG. 1A illustrates a top view (e.g., an x-y sectional view) of the white LED
package 100, and FIG. 1B illustrates a side view (e.g., an x-z sectional view) of
the white LED package 100. As shown in FIGs. 1A and 1B, the white LED package 100
may include blue LEDs 103 (e.g., two blue LEDs) and a phosphor filler 105 surrounding
the blue LEDs 103. The blue LEDs 103 and the phosphor filler 105 may be enclosed by
a package wall 101, which may form the outer casing of the white LED package 100 and
may provide mechanical protection, electrical insulation, and environmental resistance.
The package wall 101 may include a first portion 109 that is optically opaque, and
a second portion 107 that is optically transparent. The optically transparent portion
107 of the package wall 101 may be a light emission window 107 (that may be located
within an x-y plane), through which a generated white light exits the white LED package
100.
[0034] The conventional white LED package 100 may be a conventional YAG LED package, where
the phosphor filler 105 includes a YAG phosphor (that is a yellow phosphor). The YAG
phosphor may absorb a blue light emitted from the blue LEDs 103 to emit a yellow light,
which may be mixed with the blue light emitted from the blue LEDs 103 to generate
a white light.
[0035] The conventional white LED package 100 may be a conventional Potassium Fluorosilicate:Mn
4+ ("KSF") LED or Calcium Aluminum Silicon Nitride ("CASN") LED package, in which the
phosphor filler 105 may include a red phosphor and a green phosphor. The red phosphor
may be a KSF phosphor or CASN phosphor that absorbs a blue light emitted from the
blue LEDs 103 to emit a red light. The green phosphor may absorb a blue light emitted
from the blue LEDs 103 to emit a green light. The red, green, and blue lights may
be mixed to generate a white light.
[0036] VR-LCDs are often pulse driven, with a duty ratio of about 10%. For example, for
a 90Hz LCD, the frame time of a display frame is about 11 milliseconds ("ms"). That
is, the LEDs used in the BLU of the VR-LCD are only turned on for about 10% of the
frame time (i.e., about 1.1 ms), and are turned off for the remaining frame time (i.e.,
about 10 ms). The conventional YAG LED package may generally exhibit a fast turn-on
and turn-off speed, with a switching time of less than 1 ms. Although the conventional
YAG LED package can be used in the BLU of the VR-LCD, only the sRGB color gamut may
be achieved.
[0037] The conventional KSF LED package may possess a slower turn-on and turn-off speed,
with a switching time exceeding 12 ms, rendering them unsuitable for use in the BLU
of the VR-LCD. The conventional CASN LED package may feature fast turn-on and turn-off
speeds, making them a potential candidate for the BLU of the VR-LCD. However, due
to the broad spectrum of the red light generated by the red phosphor (i.e., the CASN
photoshop) absorbing the blue light, the conventional CASN LED package may not be
able to achieve the DCI-P3 color gamut. It is challenging to provide a satisfactory
solution available for achieving the DCI-P3 color gamut in VR-LCDs.
[0038] Additionally, in conventional white LED packages, blue LEDs wired in series are connected
end to end (e.g., the negative electrode of the first LED is connected to the positive
electrode of the second LED, and so on), and the driving currents of the blue LEDs
are the same. Thus, adjusting the color, such as the white point, of the emitted white
light from the conventional white LED packages may be challenging or limited.
[0039] In view of the limitations of the conventional technologies, the present disclosure
provides a white LED package that achieves the DCI-P3 color gamut and reduces the
LED cost adder. The white LED package may have potential applications in the BLU of
VR-LCDs. In the following, various white LED packages that achieve the DCI-P3 color
gamut will be explained. The design principle and driving mechanism of the disclosed
white LED packages may be applied to other suitable light-emitting element package
for generating a white light and achieving the DCI-P3 color gamut.
[0040] FIGs. 2A and 2B illustrate schematic diagrams of a white LED package 200, according
to an embodiment of the present disclosure. FIG. 2A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 200, and FIG. 2B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 200. As shown in FIGs.
2A and 2B, the white LED package 200 may include a package housing (or package wall)
201 defining a space that accommodate a blue LED 203, a red LED 213, and a green phosphor
filler 205 disposed inside the package housing 201. The package housing 201 may form
the outer casing of the white LED package 200 and provide mechanical protection, electrical
insulation, and environmental resistance. In some embodiments, the package housing
201 may include a substrate 211, a side wall 209, and a light emission window 207
(e.g., located within an x-y plane) facing the substrate 211. In some embodiments,
the substrate 211 and the side wall 209 may be optically opaque, and the light emission
window 207 may be optically transparent, through which a generated white light exits
the white LED package 200.
[0041] In some embodiments, the blue LED 203 and the red LED 213 may be disposed at the
substate 211 (e.g., directly on or indirectly on the substrate 211), and the green
phosphor filler 205 may be disposed at least partially over the blue LED 203 and the
red LED 213. For discussion purposes, FIGs. 2A and 2B show that the green phosphor
filler 205 is disposed surrounding the blue LED 203 and the red LED 213, and filling
substantially the entire space defined by the packaging house 201. Each of the blue
LED 203 and the red LED 213 may include a suitable type of LEDs, such as an LED, a
mini LED, or a micro-LED ("µ-LED"), etc. The white LED package 200 may also include
a plurality of electrodes, e.g., a first electrode 202a, a second electrode 202b,
a third electrode 202c, and a fourth electrode 202d. The electrodes 202a-202d may
be electrically connected to respective LED driving circuits (shown in FIG. 2C and
described below). In some embodiments, the white LED package 200 may also include
a controller 250 configured to individually control the respective LED driving circuits.
[0042] The blue LED 203 may be configured to emit a first light having a blue wavelength
range with a peak wavelength ranging from about 440 nm to about 480 nm. The red LED
213 may be configured to emit a second light having a red wavelength range with a
peak wavelength ranging from about 610 nm to about 680 nm. The green phosphor filler
205 may be configured to absorb at least a portion of the first light to emit a third
light having a green wavelength range. The green wavelength range may have a peak
wavelength ranging from about 510 nm to about 570 nm. For discussion purposes, in
the following description, the first light having the blue wavelength range with the
peak wavelength ranging from about 440 nm to about 480 nm may be referred to as a
blue light, the second light having the red wavelength range with the peak wavelength
ranging from about 610 nm to about 680 nm may be referred to as a red light, and the
third light having the green wavelength range with the peak wavelength ranging from
about 510 nm to about 570 nm may be referred to as a green light. The green phosphor
filler 205 may not absorb the red light output from the red LED 213. The red light
output from the red LED 213, the blue light output from the blue LED 203, and the
green light output from the green phosphor filler 205 may be mixed to generate a white
light 220 that exits the white LED package 200 through the light emission window 207.
[0043] The white LED package 200 may not include a red phosphor. The red light in the white
LED package 200 may be directly emitted from the red LED 213, or directly generated
by the red LED 213, rather than being emitted from a red phosphor that absorbs the
blue light in the conventional KSF LED or CASN LED package. The red light directly
emitted by the red LED 213 may have a narrower spectrum (or bandwidth) than the red
light generated by a red phosphor absorbing the blue light in the conventional KSF
LED or CASN LED package. Thus, the white LED package 200 may achieve the DCI-P3 color
gamut. The white LED package 200 may be applied to edge-lit BLUs of VR-LCDs, for achieving
the DCI-P3 color gamut.
[0044] FIG. 2C illustrates driving circuits of the white LED package 200, according to an
embodiment of the present disclosure. As shown in FIG. 2C, the blue LED 203 and the
red LED 213 may not be connected in series. The blue LED 203 and the red LED 213 may
be individually or independently drivable. The blue LED 203 and the red LED 213 may
have individual driving circuits, and the driving currents provided by the driving
circuits to the blue LED 203 and the red LED 213 may be individually or independently
adjustable via the controller 250. The driving currents provided to the blue LED 203
and the red LED 213 may be the same, or may be different.
[0045] For example, in the embodiment shown in FIG. 2C, the first electrode 202a and the
second electrode 202b may be an anode and a cathode of the blue LED 203, respectively,
which may be electrically connected to a first driving circuit. The third electrode
202c and the fourth electrode 202d may be an anode and a cathode of the red LED 213,
respectively, which may be electrically connected to a second driving circuit that
is different from the first driving circuit. In some embodiments, the cathode (e.g.,
second electrode 202b) of the blue LED 203 and the cathode (e.g., fourth electrode
202d) of the red LED 213 may be electrically connected, whereas the anode (e.g., first
electrode 202a) of the blue LED 203 and the anode (e.g., third electrode 202c) of
the red LED 213 may be separately connected to different driving circuits.
[0046] In the disclosed embodiment, a color (e.g., white point) of the white light 220 output
from the white LED package 200 may be adjustable via adjusting the ratio of the red
light output from the red LED 213, the blue light output from the blue LED 203, and
the green light output from the green phosphor filler 205 in the white light 220.
In some embodiments, the driving currents provided to the blue LED 203 and the red
LED 213 may be individually adjustable, through which the ratio of the red light output
from the red LED 213, the blue light output from the blue LED 203, and the green light
output from the green phosphor filler 205 in the white light 220 may be adjustable.
In some embodiments, the concentration of the phosphor filler may be adjustable, through
which the ratio of the red light output from the red LED 213, the blue light output
from the blue LED 203, and the green light output from the green phosphor filler 205
in the white light 220 may be adjustable. Accordingly, a color (e.g., white point)
of the white light 220 output from the white LED package 200 may be adjustable.
[0047] FIGs. 3A and 3B illustrate schematic diagrams of a white LED package 300, according
to an embodiment of the present disclosure. FIG. 3A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 300, and FIG. 3B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 300. FIG. 3C illustrates
driving circuits of the white LED package 300, according to an embodiment of the present
disclosure. The white LED package 300 shown in FIGs. 3A-3C may include elements, structures,
and/or functions that are the same as or similar to those included in the white LED
package 200 shown in FIGs. 2A-2C. Descriptions of the same or similar elements, structures,
and/or functions can refer to the above descriptions rendered in connection with FIGs.
2A-2C.
[0048] As shown in FIGs. 3A and 3B, the white LED package 300 may include the package housing
(or package wall) 201 defining a space. The white LED package 300 may also include
two blue LEDs 203-1 and 203-2 (collectively referred to as 203), the red LED 213,
and the green phosphor filler 205 disposed inside the package housing 201 that may
fill substantially the entire space defined by the package housing 201. In some embodiments,
the two blue LEDs 203 and the red LED 213 may be disposed at the substate 211 (e.g.,
directly on or indirectly on the substrate 211), and the green phosphor filler 205
may be disposed at least partially over the blue LEDs 203 and the red LED 213. For
discussion purposes, FIGs. 3A and 3B show that the green phosphor filler 205 is disposed
surrounding the blue LEDs 203 and the red LED 213. The white LED package 300 may also
include the electrodes 202a-202d that are electrically connected to respective LED
driving circuits.
[0049] The red LED 213 may be configured to emit a red light. The blue LEDs 203 may be configured
to emit a blue light. The green phosphor filler 205 may be configured to absorb at
least a portion of the blue light emitted by the blue LEDs 203, and at least partially
convert the absorbed blue light into a green light. The green phosphor filler 205
may not absorb the red light output from the red LED 213. The red light output from
the red LED 213, the blue light output from the blue LEDs 203, and the green light
output from the green phosphor filler 205 may be mixed to generate a white light 320,
which exits the white LED package 300 through the light emission window 207.
[0050] In some embodiments, the two blue LEDs 203 and the red LED 213 may be aligned along
a same row or line (e.g., in the x-y plane). In some embodiments, the red LED 213
may be disposed between the blue LED 203-1 and the blue LED 203-2. The blue LED 203-1
and the blue LED 203-2 may be electrically connected to one another via a connection
wire 305. In some embodiments, the red LED 213 may have a size that is greater than
the blue LEDs 203, e.g., the size of the red LED 213 may be two times of the size
of each of the blue LEDs 203 (in some embodiments, the blue LEDs 203 may have the
same size). The blue LEDs 203 and the red LED 213 may be individually or independently
driven, e.g., via the controller 250. The electrically connected blue LED 203-1 and
blue LED 203-2 may be driven in series, via a first driving circuit, while the red
LED 213 may be driven separately, via a second, different driving circuit. The driving
currents of the blue LEDs 203 and the red LED 213 may be individually or independently
adjustable. Thus, the ratio of the red light output from the red LED 213, the blue
light output from the blue LEDs 203, and the green light output from the green phosphor
filler 205 in the white light 320 may be adjustable. Accordingly, a color (e.g., white
point) of the white light 320 output from the white LED package 300 may be adjustable.
[0051] For example, in the embodiment shown in FIG. 3C, the first electrode 202a may be
the anode of the blue LED 203-1, and the fourth electrode 202d may be the cathode
of the blue LED 203-2, with the cathode of the blue LED 203-1 electrically connected
to the anode of the blue LED 203-2 (thus, the blue LEDs 203-1 and 203-2 may be connected
in series). The first electrode 202a and the fourth electrode 202d may be electrically
connected to the first driving circuit for the blue LEDs 203. The second electrode
202b and the third electrode 202c may be the anode and the cathode of the red LED
213, respectively, which may be electrically connected to the second driving circuit.
In some embodiments, the cathode (e.g., fourth electrode 202d) of the blue LED 203-2
and the cathode (e.g., third electrode 202c) of the red LED 213 may be electrically
connected, whereas the anode (e.g., first electrode 202a) of the blue LED 203-1 and
the anode (e.g., second electrode 202b) of the red LED 213 may be separately connected
to different driving circuits.
[0052] In some embodiments, the concentration of the green phosphor filler 205 may be adjustable,
through which the ratio of the red light output from the red LED 213, the blue light
output from the blue LED 203, and the green light output from the green phosphor filler
205 in the white light 320 may be adjustable. Accordingly, a color (e.g., white point)
of the white light 320 output from the white LED package 200 may be adjustable.
[0053] FIGs. 4A and 4B illustrate schematic diagrams of a white LED package 400, according
to an embodiment of the present disclosure. FIG. 4A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 400, and FIG. 4B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 400. FIG. 4C illustrates
driving circuits of the white LED package 400, according to an embodiment of the present
disclosure. The white LED package 400 shown in FIGs. 4A-4C may include elements, structures,
and/or functions that are the same as or similar to those included in the white LED
package 200 shown in FIGs. 2A-2C or the white LED package 300 shown in FIGs. 3A-3C.
Descriptions of the same or similar elements, structures, and/or functions can refer
to the above descriptions rendered in connection with FIGs. 2A-2C or FIGs. 3A-3C.
[0054] As shown in FIGs. 4A and 4B, the white LED package 400 may include the package housing
(or package wall) 201, the two blue LEDs 203-1 and 203-2 (collectively referred to
as 203), two red LEDs 213-1 and 213-2 (collectively referred to as 213), and the green
phosphor filler 205. The white LED package 400 may also include the electrodes 202a-202d
that are electrically connected to respective LED driving circuits. The red light
output from the red LED 213, the blue light output from the blue LEDs 203, and the
green light output from the green phosphor filler 205 may be mixed to generate a white
light 420.
[0055] In some embodiments, the two blue LEDs 203 and the two red LEDs 213 may be aligned
along a same row or line (e.g., in the x-y plane). In some embodiments, the two blue
LEDs 203 and the two red LEDs 213 may be arranged in an alternating pattern (or interleaving
configuration), as shown in FIG. 4A. In some embodiments, the sizes of the red LEDs
213 may be the same, and the sizes of the blue LEDs 203 may be the same. In some embodiments,
the size of each red LED 213 may be substantially the same as the size of each blue
LED 203. In some embodiments, the size of each red LED 213 may be different from the
size of each blue LED 203. The blue LED 203-1 and the blue LED 203-2 may be electrically
connected to one another via the connection wire (referred to as a first connection
wire) 305. The red LED 213-1 and the red LED 213-2 may be electrically connected to
one another via a second, different connection wire 405. The blue LEDs 203 and the
red LEDs 213 may be individually or independently driven, e.g., via the controller
250. For example, the two electrically connected blue LED 203-1 and blue LED 203-2
may be driven in series, via a first driving circuit, and the two electrically connected
red LED 213-1 and red LED 213-2 may be driven in series, via a second, different driving
circuit. The driving currents of the blue LEDs 203 and the red LEDs 213 may be individually
or independently adjustable. Thus, the ratio of the red light output from the red
LEDs 213, the blue light output from the blue LEDs 203, and the green light output
from the green phosphor filler 205 in the white light 420 may be adjustable. Accordingly,
a color (e.g., white point) of the white light 420 output from the white LED package
400 may be adjustable.
[0056] For example, as shown in FIG. 4C, the first electrode 202a may be the anode of the
blue LED 203-1, and the third electrode 202c may be the cathode of the blue LED 203-2,
with the cathode of the blue LED 203-1 electrically connected to the anode of the
blue LED 203-2. The first electrode 202a and the third electrode 202c may be electrically
connected to the first driving circuit for driving the blue LEDs 203. The second electrode
202b may be the anode of the red LED 213-1, and the fourth electrode 202d may be the
cathode of the red LED 213-2, with the cathode of the red LED 213-1 electrically connected
to the anode of the red LED 213-2. The second electrode 202b and the fourth electrode
202d may be electrically connected to the second driving circuit for driving the red
LEDs 213. In some embodiments, the cathode (e.g., third electrode 202c) of the blue
LED 203-2 and the cathode (e.g., fourth electrode 202d) of the red LED 213-2 may be
electrically connected, whereas the anode (e.g., first electrode 202a) of the blue
LED 203-1 and the anode (e.g., second electrode 202b) of the red LED 213-1 may be
separately connected to different driving circuits.
[0057] In some embodiments, the concentration of the green phosphor filler 205 may be adjustable,
through which the ratio of the red light output from the red LEDs 213, the blue light
output from the blue LEDs 203, and the green light output from the green phosphor
filler 205 in the white light 420 may be adjustable. Accordingly, a color (e.g., white
point) of the white light 420 output from the white LED package 400 may be adjustable.
[0058] FIGs. 5A and 5B illustrate schematic diagrams of a white LED package 500, according
to an embodiment of the present disclosure. FIG. 5A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 500, and FIG. 5B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 500. FIG. 5C illustrates
driving circuits of the white LED package 500, according to an embodiment of the present
disclosure. The white LED package 500 shown in FIGs. 5A-5C may include elements, structures,
and/or functions that are the same as or similar to those included in the white LED
package 200 shown in FIGs. 2A-2C, the white LED package 300 shown in FIGs. 3A-3C,
or the white LED package 400 shown in FIGs. 4A-4C. Descriptions of the same or similar
elements, structures, and/or functions can refer to the above descriptions rendered
in connection with FIGs. 2A-2C, FIGs. 3A-3C, or FIGs. 4A-4C.
[0059] As shown in FIGs. 5A and 5B, the white LED package 500 may include the package housing
(or package wall) 201, the two blue LEDs 203-1 and 203-2 (collectively referred to
as 203), the two red LEDs 213-1 and 213-2 (collectively referred to as 213), and the
green phosphor filler 205. The two blue LEDs 203, the two red LEDs 213, and the green
phosphor filler 205 may be enclosed by the package housing 201. The white LED package
500 may also include the electrodes 202a-202d that are electrically connected to respective
LED driving circuits. The two blue LEDs 203 and the two red LEDs 213 may be aligned
along a same row or line. The blue LED 203-1 and the blue LED 203-2 may be electrically
connected to one another via the first connection wire 305. The red LED 213-1 and
the red LED 213-2 may be electrically connected to one another via the second connection
wire 405. Different from the white LED package 400 shown in FIGs. 4A-4C, in the embodiment
shown in FIGs. 5A and 5B, the two blue LEDs 203 may be arranged side by side, and
the two red LEDs 213 may be arranged side by side. The red light output from the red
LEDs 213, the blue light output from the blue LEDs 203, and the green light output
from the green phosphor filler 205 may be mixed to generate a white light 520 that
exits the white LED package 500 through the light emission window 207.
[0060] Similar to the white LED package 400 shown in FIGs. 4A-4C, the two electrically connected
blue LED 203-1 and blue LED 203-2 may be driven in series, via the first driving circuit,
and the two electrically connected red LED 213-1 and red LED 213-2 may be driven in
series, via the second driving circuit, as shown in FIG. 5C. The driving currents
of the blue LEDs 203 and the red LEDs 213 may be individually or independently adjustable.
Thus, the ratio of the red light output from the red LEDs 213, the blue light output
from the blue LEDs 203, and the green light output from the green phosphor filler
205 in the white light 520 may be adjustable. Accordingly, a color (e.g., white point)
of the white light 520 output from the white LED package 500 may be adjustable.
[0061] For example, in the embodiment shown in FIG. 5C, the first electrode 202a may be
the anode of the blue LED 203-1, and the second electrode 202b may be the cathode
of the blue LED 203-2, with the cathode of the blue LED 203-1 electrically connected
to the anode of the blue LED 203-2. The first electrode 202a and the second electrode
202b may be electrically connected to the first driving circuit for the blue LEDs
203. The third electrode 202c may be the anode of the red LED 213-1, and the fourth
electrode 202d may be the cathode of the red LED 213-2, with the cathode of the red
LED 213-1 electrically connected to the anode of the red LED 213-2. The third electrode
202c and the fourth electrode 202d may be electrically connected to the second driving
circuit. In some embodiments, the cathode (e.g., second electrode 202b) of the blue
LED 203-2 and the cathode (e.g., fourth electrode 202d) of the red LED 213-2 may be
electrically connected, whereas the anode (e.g., first electrode 202a) of the blue
LED 203-1 and the anode (e.g., third electrode 202c) of the red LED 213-1 may be separately
connected to different driving circuits.
[0062] FIGs. 6A and 6B illustrate schematic diagrams of a white LED package 600, according
to an embodiment of the present disclosure. FIG. 6A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 600, and FIG. 6B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 600. FIG. 6C illustrates
driving circuits of the white LED package 600, according to an embodiment of the present
disclosure. The white LED package 600 shown in FIGs. 6A-6C may include elements, structures,
and/or functions that are the same as or similar to those included in the white LED
package 200 shown in FIGs. 2A-2C, the white LED package 300 shown in FIGs. 3A-3C,
the white LED package 400 shown in FIGs. 4A-4C, or the white LED package 500 shown
in FIGs. 5A-5C. Descriptions of the same or similar elements, structures, and/or functions
can refer to the above descriptions rendered in connection with FIGs. 2A-2C, FIGs.
3A-3C, FIGs. 4A-4C, or FIGs. 5A-5C.
[0063] As shown in FIGs. 6A and 6B, the white LED package 600 may include the package housing
(or package wall) 201, the two blue LEDs 203-1 and 203-2 (collectively referred to
as 203), the red LED 213, and the green phosphor filler 205. The blue LED 203-1 and
the blue LED 203-2 may be electrically connected to one another via the first connection
wire 305. The two blue LEDs 203, the red LED 213, and the green phosphor filler 205
may be enclosed by the package housing 201. The white LED package 600 may also include
the electrodes 202a-202d that are electrically connected to respective LED driving
circuits.
[0064] In some embodiments, the two blue LEDs 203 and the red LED 213 may be aligned along
a same row or line. Different from the white LED package 300 shown in FIGs. 3A-3C,
in the embodiment shown in FIGs. 6A and 6B, the two blue LEDs 203 may be arranged
side by side, and the red LED 213 may be disposed at a side of the two blue LEDs 203,
rather than being disposed between the two blue LEDs 203 as shown in FIG. 3A. The
red light output from the red LED 213, the blue light output from the blue LEDs 203,
and the green light output from the green phosphor filler 205 may be mixed to generate
a white light 620 that exits the white LED package 600 through the light emission
window 207. Similar to the white LED package 300 shown in FIGs. 3A-3C, the two electrically
connected blue LED 203-1 and blue LED 203-2 may be driven in series, via the first
driving circuit, and the red LED 213 may be driven separately, via the second driving
circuit, as shown in FIG. 6C. The driving currents of the blue LEDs 203 and the red
LED 213 may be individually or independently adjustable.
[0065] For example, in the embodiment shown in FIG. 6C, the first electrode 202a may be
the anode of the blue LED 203-1, and the second electrode 202b may be the cathode
of the blue LED 203-2, with the cathode of the blue LED 203-1 electrically connected
to the anode of the blue LED 203-2. The first electrode 202a and the second electrode
202b may be electrically connected to the first driving circuit for driving the two
blue LEDs 203. The third electrode 202c and the fourth electrode 202d may be the anode
and the cathode of the red LED 213, respectively, which may be electrically connected
to the second driving circuit for driving the red LED 213. In some embodiments, the
cathode (e.g., second electrode 202b) of the blue LED 203-2 and the cathode (e.g.,
fourth electrode 202d) of the red LED 213 may be electrically connected, whereas the
anode (e.g., first electrode 202a) of the blue LED 203-1 and the anode (e.g., third
electrode 202c) of the red LED 213 may be separately connected to different driving
circuits.
[0066] FIGs. 7A-7C illustrate schematic diagrams of a white LED package 700, according to
an embodiment of the present disclosure. FIG. 7A illustrates a top view (e.g., an
x-y sectional view) of the white LED package 700. FIG. 7B illustrates a side view
(e.g., an x-z sectional view) of the white LED package 700, with the viewpoint oriented
towards a +y-axis direction, showing the two blue LEDs 203 (the red LED is not visible).
FIG. 7C illustrates a side view (e.g., the x-z sectional view) of the white LED package
700, with the viewpoint oriented towards a -y-axis direction, showing the red LED
213 (the blue LEDs 203 are not visible). The white LED package 700 shown in FIGs.
7A-7C may include elements, structures, and/or functions that are the same as or similar
to those included in the white LED package 200 shown in FIGs. 2A-2C, the white LED
package 300 shown in FIGs. 3A-3C, the white LED package 400 shown in FIGs. 4A-4C,
the white LED package 500 shown in FIGs.5A-5C, or the white LED package 600 shown
in FIGs. 6A-6C. Descriptions of the same or similar elements, structures, and/or functions
can refer to the above descriptions rendered in connection with FIGs. 2A-2C, FIGs.
3A-3C, FIGs. 4A-4C, FIGs. 5A-5C, or FIGs. 6A-6C.
[0067] As shown in FIGs. 7A-7C, the white LED package 700 may include the package housing
(or package wall) 201, the two blue LEDs 203-1 and 203-2 (collectively referred to
as 203), the red LED 213, and the green phosphor filler 205. The blue LED 203-1 and
the blue LED 203-2 may be electrically connected to one another via the first connection
wire 305. The two blue LEDs 203, the red LED 213, and the green phosphor filler 205
may be enclosed by the package housing 201. The white LED package 700 may also include
the electrodes 202a-202d that are electrically connected to respective LED driving
circuits.
[0068] Different from the white LED package 600 shown in FIGs. 6A-6C, in the embodiment
shown in FIGs. 7A-7C, the two blue LEDs 203 may be arranged side by side, aligned
along a first row (or line), while the red LED 213 may be aligned in a second row
(or line) parallel with the first row (or line). The red LED 213 may have a size that
is greater than the blue LED 203, e.g., the size of the red LED 213 may be two times
of the size of the blue LED 203. The red light output from the red LED 213, the blue
light output from the blue LEDs 203, and the green light output from the green phosphor
filler 205 may be mixed to generate a white light 720 that exits the white LED package
700 through the light emission window 207.
[0069] Similar to the white LED package 600 shown in FIGs. 6A-6C, in the white LED package
700, the two electrically connected blue LED 203-1 and blue LED 203-2 may be driven
in series, via the first driving circuit, and the red LED 213 may be driven separately,
via the second driving circuit, as shown in FIG. 7C. The driving currents of the blue
LEDs 203 and the red LED 213 may be individually or independently adjustable. The
driving circuits of the white LED package 700 may be similar to that shown in FIG.
6C, and the details of the driving circuits of the white LED package 700 may refer
to the description of FIG. 6C.
[0070] FIGs. 8A and 8B illustrate schematic diagrams of a white LED package 800, according
to an embodiment of the present disclosure. FIG. 8A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 800, and FIG. 8B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 800. FIG. 8C illustrates
driving circuits of the white LED package 800, according to an embodiment of the present
disclosure. The white LED package 800 shown in FIGs. 8A-8C may include elements, structures,
and/or functions that are the same as or similar to those included in the white LED
package 200 shown in FIGs. 2A-2C, the white LED package 300 shown in FIGs. 3A-3C,
the white LED package 400 shown in FIGs. 4A-4C, the white LED package 500 shown in
FIGs. 5A-5C, the white LED package 600 shown in FIGs. 6A-6C, or the white LED package
700 shown in FIGs. 7A-7C. Descriptions of the same or similar elements, structures,
and/or functions can refer to the above descriptions rendered in connection with FIGs.
2A-2C, FIGs. 3A-3C, FIGs. 4A-4C, FIGs. 5A-5C, FIGs. 6A-6C, or FIGs. 7A-7C.
[0071] As shown in FIGs. 8A and 8B, the white LED package 800 may include the package housing
(or package wall) 201, the two blue LEDs 203-1 and 203-2 (collectively referred to
as 203), the two red LEDs 213-1 and 213-2 (collectively referred to as 213), and the
green phosphor filler 205. The two blue LEDs 203, the two red LEDs 213, and the green
phosphor filler 205 may be enclosed by the package housing 201. The white LED package
800 may also include the electrodes 202a-202d that are electrically connected to respective
LED driving circuits. The blue LED 203-1 and the blue LED 203-2 may be electrically
connected to one another via the first connection wire 305. The red LED 213-1 and
the red LED 213-2 may be electrically connected to one another via the second connection
wire 405. The two blue LEDs 203 may be aligned along a first row (or line), and the
two red LEDs 213 may be aligned along a second row or line.
[0072] Different from the white LED package 500 shown in FIGs. 5A and 5B (in the top view
of FIG. 5A, the two blue LEDs 203 and the two red LEDs 213 are aligned along a same
line or row), in the embodiment shown in FIGs. 8A and 8B, the two blue LEDs 203 may
be arranged side by side, aligned along a first row (or line), while the two red LED
213 may be arranged side by side, aligned along a second row (or line) parallel with
the first row (or line). In some embodiments, the red LED 213 may have a size that
is substantially the same as the blue LED 203.
[0073] Similar to the white LED package 500 shown in FIGs. 5A-5C, in the white LED package
800, as shown in FIG. 8C, the two electrically connected blue LED 203-1 and blue LED
203-2 may be driven in series, via the first driving circuit, and the two electrically
connected red LED 213-1 and red LED 213-2 may be driven in series, via the second
driving circuit. The driving currents of the blue LEDs 203 and the red LEDs 213 may
be individually or independently adjustable. For example, in the embodiment shown
in FIG. 8C, the first electrode 202a may be the anode of the blue LED 203-1, and the
third electrode 202c may be the cathode of the blue LED 203-2, with the cathode of
the blue LED 203-1 electrically connected to the anode of the blue LED 203-2. The
first electrode 202a and the third electrode 202c may be electrically connected to
the first driving circuit for the blue LEDs 203. The second electrode 202b may be
the anode of the red LED 213-1, and the fourth electrode 202d may be the cathode of
the red LED 213-2, with the cathode of the red LED 213-1 electrically connected to
the anode of the red LED 213-2. The second electrode 202b and the fourth electrode
202d may be electrically connected to the second driving circuit. In some embodiments,
the cathode (e.g., third electrode 202c) of the blue LED 203-2 and the cathode (e.g.,
fourth electrode 202d) of the red LED 213-2 may be electrically connected, whereas
the anode (e.g., first electrode 202a) of the blue LED 203-1 and the anode (e.g.,
second electrode 202b) of the red LED 213-1 may be separately connected to different
driving circuits. The red light output from the red LEDs 213, the blue light output
from the blue LEDs 203, and the green light output from the green phosphor filler
205 may be mixed to generate a white light 820 that exits the white LED package 800
through the light emission window 207.
[0074] FIGs. 9A and 9B illustrate schematic diagrams of a white LED package 900, according
to an embodiment of the present disclosure. FIG. 9A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 900, and FIG. 9B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 900. FIG. 9C illustrates
driving circuits of the white LED package 900, according to an embodiment of the present
disclosure. The white LED package 900 shown in FIGs. 9A-9C may include elements, structures,
and/or functions that are the same as or similar to those included in the white LED
package 200 shown in FIGs. 2A-2C, the white LED package 300 shown in FIGs. 3A-3C,
the white LED package 400 shown in FIGs. 4A-4C, the white LED package 500 shown in
FIGs. 5A-5C, the white LED package 600 shown in FIGs. 6A-6C, the white LED package
700 shown in FIGs. 7A-7C, or the white LED package 800 shown in FIGs. 8A-8C. Descriptions
of the same or similar elements, structures, and/or functions can refer to the above
descriptions rendered in connection with FIGs. 2A-2C, FIGs. 3A-3C, FIGs. 4A-4C, FIGs.
5A-5C, FIGs. 6A-6C, FIGs. 7A-7C, or FIGs. 8A-8C.
[0075] As shown in FIGs. 9A and 9B, the white LED package 900 may include the package housing
(or package wall) 201, the blue LED 203, the two red LED 213-1 and 213-2 (collectively
referred to as 213), and the green phosphor filler 205. The red LED 213-1 and the
red LED 213-2 may be electrically connected to one another via the second connection
wire 405. The blue LED 203, the two red LEDs 213, and the green phosphor filler 205
may be enclosed by the package housing 201. The white LED package 900 may also include
the electrodes 202a-202d that are electrically connected to respective LED driving
circuits.
[0076] The blue LED 203 and the two red LEDs 213 may be aligned along a same row or line.
In the embodiment shown in FIGs. 9A and 9B, the two red LEDs 213 may be arranged side
by side, and the blue LED 203 and the two red LEDs 213 may be arranged side by side.
For example, the red LED 213-2 may be disposed between the red LED 213-1 and the blue
LED 203. That is, the blue LED 203 may be disposed at a side of the two red LEDs 213.
In some embodiments, although not shown, the blue LED 203 between the red LED 213-2
and the red LED 213-1. In some embodiments, the blue LED 203 may have a size that
is greater than the red LED 213, e.g., the size of the blue LED 203 may be two times
of the size of the red LED 213. The red light output from the red LEDs 213, the blue
light output from the blue LED 203, and the green light output from the green phosphor
filler 205 may be mixed to generate a white light 920 that exits the white LED package
900 through the light emission window 207.
[0077] The blue LED 203 and the two red LEDs 213 may be individually or independently driven,
e.g., via the controller 250. As shown in FIG. 9C, the two electrically connected
red LED 213-1 and red LED 213-2 may be driven in series, via the second driving circuit,
and the blue LED 203 may be driven separately, via the first driving circuit. The
driving currents of the blue LEDs 203 and the red LED 213 may be individually or independently
adjustable. For example, in the embodiment shown in FIG. 9C, the first electrode 202a
may be the anode of the red LED 213-1, and the second electrode 202b may be the cathode
of the red LED 213-2, with the cathode of the red LED 213-1 electrically connected
to the anode of the red LED 213-2. The first electrode 202a and the second electrode
202b may be electrically connected to the second driving circuit for driving the two
red LEDs 213. The third electrode 202c and the fourth electrode 202d may be the anode
and the cathode of the blue LED 203, respectively, which may be electrically connected
to the first driving circuit. In some embodiments, the cathode (e.g., second electrode
202b) of the red LED 213-2 and the cathode (e.g., fourth electrode 202d) of the blue
LED 203 may be electrically connected, whereas the anode (e.g., first electrode 202a)
of the red LED 213-1 and the anode (e.g., third electrode 202c) of the blue LED 203
may be separately connected to different driving circuits.
[0078] FIGs. 10A-10C illustrate schematic diagrams of a white LED package 1000, according
to an embodiment of the present disclosure. FIG. 10A illustrates a top view (e.g.,
an x-y sectional view) of the white LED package 1000. FIG. 10B illustrates a side
view (e.g., an x-z sectional view) of the white LED package 1000, with the viewpoint
oriented towards a +y-axis direction. FIG. 10C illustrates a side view (e.g., the
x-z sectional view) of the white LED package 1000, with the viewpoint oriented towards
a -y-axis direction. The white LED package 1000 shown in FIGs. 10A-10C may include
elements, structures, and/or functions that are the same as or similar to those included
in the white LED package 200 shown in FIGs. 2A-2C, the white LED package 300 shown
in FIGs. 3A-3C, the white LED package 400 shown in FIGs. 4A-4C, the white LED package
500 shown in FIGs. 5A-5C, the white LED package 600 shown in FIGs. 6A-6C, the white
LED package 700 shown in FIGs. 7A-7C, the white LED package 800 shown in FIGs. 8A-8C,
or the white LED package 900 shown in FIGs. 9A-9C. Descriptions of the same or similar
elements, structures, and/or functions can refer to the above descriptions rendered
in connection with FIGs. 2A-2C, FIGs. 3A-3C, FIGs. 4A-4C, FIGs. 5A-5C, FIGs. 6A-6C,
FIGs. 7A-7C, FIGs. 8A-8C, or FIGs. 9A-9C.
[0079] As shown in FIGs. 10A-10C, the white LED package 1000 may include the package housing
(or package wall) 201, the blue LED 203, the two red LED 213-1 and 213-2 (collectively
referred to as 213), and the green phosphor filler 205. The red LED 213-1 and the
red LED 213-2 may be electrically connected to one another via the second connection
wire 405. The blue LED 203, the two red LEDs 213, and the green phosphor filler 205
may be enclosed by the package housing 201. The white LED package 1000 may also include
the electrodes 202a-202d that are electrically connected to respective LED driving
circuits.
[0080] Different from the white LED package 900 shown in FIGs. 9A-9C, in the embodiment
shown in FIGs. 10A-10C, the two red LEDs 213 may be arranged side by side, aligned
along a first row (or line), while the blue LED 203 may be aligned in a second row
(or line) parallel with the first row (or line). In some embodiments, the blue LED
203 may have a size that is greater than the red LED 213, e.g., the size of the blue
LED 203 may be two times of the size of the red LED 213. The red light output from
the red LEDs 213, the blue light output from the blue LED 203, and the green light
output from the green phosphor filler 205 may be mixed to generate a white light 1020
that exits the white LED package 1000 through the light emission window 207.
[0081] Similar to the white LED package 900 shown in FIGs. 9A-9C, in the white LED package
1000, the two electrically connected red LED 213-1 and red LED 213-2 may be driven
in series, via the second driving circuit, and the blue LED 203 may be driven separately,
via the first driving circuit. The driving currents of the red LED 213 and the blue
LED 203 may be individually or independently adjustable. The driving circuits of the
white LED package 1000 may be similar to that shown in FIG. 9C, and the details of
the driving circuits of the white LED package 1000 may refer to the description of
FIG. 9C.
[0082] FIG. 11A illustrates a schematic diagram of a display system 1100, according to an
embodiment of the present disclosure. The display system 1100 may include one or more
disclosed white LED packages. As shown FIG. 11A, the display system 1100 may include
a backlight module 1107, a reflective display panel 1101, and a polarizing component
1105. For discussion purposes, the polarizing component 1105 is shown as including
a polarization beam splitter ("PBS") (also referred to as 1105 for discussion purposes).
The backlight module 1107 may output a backlight 1110 toward the PBS 1105. The backlight
1110 may be polarized and reflected as a backlight 1112 toward the reflective display
panel 1101. The reflective display panel 1101 may modulate and reflect the backlight
1112 as an image light 1114 back to the PBS 1105. The image light 1114 may have different
polarization depending on the modulation of the backlight 1112 provided by the reflective
display panel 1101. The PBS 1105 may substantially transmit or block the image light
1114 depending on the polarization state of the image light 1114. For discussion purposes,
FIG. 11A shows that the PBS 1105 reflects a linearly polarized light that is polarized
in 0° (e.g., in a y-axis direction) and transmits a linearly polarized light that
is polarized in 90° (e.g., in a z-axis direction), the backlight 1112 is a linearly
polarized light that is polarized in 0° (e.g., in the y-axis direction), and the image
light 1114 may be a linearly polarized light that is polarized in 90° (e.g., in the
z-axis direction). Thus, the PBS 1105 may substantially transmit the image light 1114.
[0083] FIG. 11B illustrates an x-y sectional view of an illuminator 1120 that may be included
in the backlight module 1107 shown in FIG. 11A, according to an embodiment of the
present disclosure. As shown in FIGs. 11A and 11B, the backlight module 1107 may include
the illuminator 1120, and a plurality of optical elements (not shown) coupled with
the illuminator 1120. The plurality of optical elements (not shown) may be configured
to condition a backlight output from the illuminator 1120 into the backlight 1110
propagating toward the PBS 1105. The illuminator 1120 may be an arrayed light source
panel including a plurality of light sources 1125. Each light source 1125 may include
an embodiment of the disclosed white LED packages. In some embodiments, the plurality
of light sources 1125 may be individually addressable, e.g., via the controller 250,
to provide dynamic zonal brightness control, and improved display performance and
power budget.
[0084] FIG. 11C illustrates a schematic diagram of a display system 1160, according to an
embodiment of the present disclosure. The display system 1160 may include one or more
disclosed white LED packages. As shown FIG. 11C, the display system 1160 may include
a backlight unit ("BLU") 1167 and a liquid crystal display ("LCD") panel 1161. The
BLU 1167 may be configured to illuminate the LCD panel 1161. The BLU 1167 may include
a light source 1170, a light guide plate 1172, a reflector sheet 1174, and an optical
film stack 1176. The light source 1170 may be disposed between the reflector sheet
1174 and the optical film stack 1176, and the optical film stack 1176 may be disposed
between the light guide plate 1172 and the LCD panel 1161. The light source 1170 may
include one or more disclosed white LED packages. For discussion purposes, the display
system 1160 is shown as an edge-lit LCD system, in which the light source 1170 is
disposed at an edge of the light guide plate 1172. The light source 1170 may be configured
to output a backlight (e.g., a white light, not shown) toward the light guide plate
1172, and the light guide plate 1172 may propagate the backlight toward the optical
film stack 1176. The optical film stack 1176 may be configured to condition the backlight
received from the light guide plate 1172 into a desirable backlight 1180, which illuminates
the LCD panel 1161. The optical film stack 1176 may include one or more optical films
arranged in a stack, e.g., a diffuser film, a first prism film, and a second prism
film arranged in a stack.
[0085] FIG. 12A illustrates a schematic diagram of an artificial reality system 1200, according
to an embodiment of the present disclosure. The artificial reality system 1200 may
present VR, AR, and/or MR content to a user, such as images, video, audio, or a combination
thereof. In some embodiments, the artificial system 1200 may be configured to be worn
on a head of a user (e.g., by having the form of spectacles or eyeglasses, as shown
in FIG. 12A), or to be included as part of a helmet that is worn by the user. In some
embodiments, the artificial system 1200 may be referred to as a head-mounted display.
In some embodiments, the artificial system 1200 may be configured for placement in
proximity of an eye or eyes of the user at a fixed location in front of the eye(s),
without being mounted to the head of the user. For example, the artificial system
1200 may be mounted in a vehicle, such as a car or an airplane, at a location in front
of an eye or eyes of the user.
[0086] For discussion purposes, FIG. 12A shows that the artificial reality system 1200 includes
a frame 1205 configured to mount to a head of a user, and left-eye and right-eye display
systems 1210L and 1210R mounted to the frame 1205. The frame 1205 is merely an example
structure to which various components of the artificial reality system 1200 may be
mounted. Other suitable type of fixtures may be used in place of or in combination
with the frame 1205. The left-eye and right-eye display systems 1210L and 1210R may
be customized to a variety of shapes and sizes to conform to different styles of the
frame 1205.
[0087] FIG. 12B is a cross-sectional view of half of the artificial reality system 1200
shown in FIG. 12A according to an embodiment of the present disclosure. For illustrative
purposes, FIG. 12B shows the cross-sectional view associated with the right-eye display
system 1210R. Referring to FIGs. 12A and 12B, each of the left-eye display system
1210L and the right-eye display system 1210R may be configured to project a virtual
image through an eye-box region 1260 of the system 1200. Each of the left-eye display
system 1210L and the right-eye display system 1210R may include a backlight module,
a display panel, and a plurality of suitable optical elements. The backlight module
may include an illuminator, which may be an arrayed light source panel including a
plurality of disclosed white LED packages. In some embodiments, the illuminator may
provide dynamic zonal brightness control, enhancing the display performance and power
budget. The eye-box region 1260 is a region in space where an eye 1259 of the user
is positioned to perceive the virtual image projected by the left-eye display system
1210L or the right-eye display system 1210R. The eye-box region 1260 may include one
or more exit pupils 1257. The left-eye display system 1210L or the right-eye display
system 1210R may project the virtual image through the one or more exit pupils 1257,
and an eye pupil 1258 may be positioned at the one or more exit pupils 1257 to perceive
the virtual image.
[0088] FIG. 12C is a detailed cross-sectional view of the artificial reality system 1200
shown in FIG. 12A, according to an embodiment of the present disclosure. Referring
to FIG. 12A and FIG. 12C, each of the left-eye display system 1210L and the right-eye
display system 1210R may be configured to project a virtual image through the eye-box
region 1260 of the corresponding display system 1210L or 1210R. In some embodiments,
each of the left-eye display system 1210L and the right-eye display system 1210R may
be an embodiment of the display system 1160 shown in FIG. 11C. For example, each of
the left-eye display system 1210L and the right-eye display system 1210R may include
a backlight unit and a display panel (e.g., an LCD panel). The display system 1210L
or 1210R may display virtual (i.e., computer-generated) images to a user.
[0089] In some embodiments, the artificial reality system 1200 may also include a viewing
optics assembly 1220, an object tracking system 1230, and a controller 1240 (e.g.,
a controller similar to the controller 250). The viewing optics assembly 1220 may
be arranged between the display system 1210L or 1210R and eyes 1259, and may be configured
to guide an image light output from the display system 1210L or 1210R to the eye-box
region 1260. The image light may represent a virtual image displayed on the display
system 1210L or 1210R. In some embodiments, the viewing optics assembly 1220 may include
two lens assemblies 1225 for the left and right eyes 1259, respectively. The object
tracking system 1230 may be an eye tracking system and/or face tracking system. The
object tracking system 1230 may include an infrared ("IR") light source 1231 configured
to emit an IR light to illuminate the eyes 1259 and/or the face. The object tracking
system 1230 may also include an optical sensor 1233, such as a camera, configured
to receive the IR light reflected by each eye 1259 and generate a tracking signal
relating to the eye 1259, such as an image of the eye 1259. In some embodiments, the
object tracking system 1230 may also include an IR deflecting element (not shown)
configured to deflect the IR light reflected by the eye 1259 toward the optical sensor
1233. The controller 1240 may be communicatively coupled with the display system 1210L
or 1210R, the viewing optics assembly 1220, and/or the object tracking system 1230
to control the operations thereof.
[0090] In some embodiments, the lens assembly 1225 may be configured to mitigate the accommodation-vergence
conflict in the system 1200. For example, the display systems 1210L and 1210R may
be synchronized to display respective virtual images including a same virtual object.
The virtual objects may be located in different positions in the respective virtual
images, or the respective virtual images may show different perspectives of the virtual
object. Based on the eye tracking information provided by the eye tracking system
1230, the controller 1240 may determine a vergence depth (dv) of the gaze of the user
that verges on a virtual object 1218, based on the gaze point or an estimated intersection
of gaze lines 1219 determined by the object tracking system 1230. As shown in FIG.
12C, the gaze lines 1219 may converge or intersect at the distance dv, where the virtual
object 1218 is located. The controller 1240 may control the lens assemblies 1225 to
adjust the optical power to provide an accommodation that matches the vergence depth
(dv) associated with the virtual object 1218, thereby reducing the accommodation-vergence
conflict in the system 1200. For example, the controller 1240 may control the lens
assembly 1225 to provide an optical power corresponding to a focal plane or an image
plane of the display systems 1210L and 1210R that matches with the vergence depth
(dv).
[0091] The foregoing description of the embodiments of the present disclosure have been
presented for the purpose of illustration. It is not intended to be exhaustive or
to limit the disclosure to the precise forms disclosed. Persons skilled in the relevant
art can appreciate that modifications and variations are possible in light of the
above disclosure.
[0092] Further, when an embodiment illustrated in a drawing shows a single element, it is
understood that the embodiment or an embodiment not shown in the figures but within
the scope of the present disclosure may include a plurality of such elements. Likewise,
when an embodiment illustrated in a drawing shows a plurality of such elements, it
is understood that the embodiment or an embodiment not shown in the figures but within
the scope of the present disclosure may include only one such element. The number
of elements illustrated in the drawing is for illustration purposes only, and should
not be construed as limiting the scope of the embodiment. Moreover, unless otherwise
noted, the embodiments shown in the drawings are not mutually exclusive, and they
may be combined in any suitable manner. For example, elements shown in one figure/embodiment
but not shown in another figure/embodiment may nevertheless be included in the other
figure/embodiment. In any optical device disclosed herein including one or more optical
layers, films, plates, or elements, the numbers of the layers, films, plates, or elements
shown in the figures are for illustrative purposes only. In other embodiments not
shown in the figures, which are still within the scope of the present disclosure,
the same or different layers, films, plates, or elements shown in the same or different
figures/embodiments may be combined or repeated in various manners to form a stack.
[0093] Various embodiments have been described to illustrate the exemplary implementations.
Based on the disclosed embodiments, a person having ordinary skills in the art may
make various other changes, modifications, rearrangements, and substitutions without
departing from the scope of the present disclosure. Thus, while the present disclosure
has been described in detail with reference to the above embodiments, the present
disclosure is not limited to the above described embodiments. The present disclosure
may be embodied in other equivalent forms without departing from the scope of the
present disclosure. The scope of the present disclosure is defined in the appended
claims.